Barcode Detection

Automatically detects and decodes barcodes in document images. Supports QR codes, DataMatrix, PDF417, and 1D barcode formats. Cross-validates barcode data against MRZ and visual inspection zone (VIZ) data to detect tampering.

How It Works

1. Document image is analyzed for barcodes during document upload
2. All barcodes in the image are detected and decoded
3. PDF417 barcodes (US/Canadian driver's licenses) are parsed using AAMVA format
4. Barcode data is cross-validated against MRZ data for consistency
5. Discrepancies are flagged as potential document tampering

Barcode detection runs automatically as part of the document verification pipeline. No additional API call is needed.

Supported Formats

Format	Usage	Cross-Validation
QR Code	EU digital IDs, some visas	JSON payload compared to MRZ
DataMatrix	Visas, residence permits	Compared to MRZ
PDF417	US/Canadian driver's licenses	AAMVA fields compared to MRZ
EAN-13	Product barcodes	Detected but not cross-validated
EAN-8	Product barcodes	Detected but not cross-validated
Code 128	Shipping labels, visas	Detected but not cross-validated
Code 39	Military IDs, some licenses	Detected but not cross-validated
ITF	Logistics barcodes	Detected but not cross-validated

AAMVA PDF417 Parsing

US and Canadian driver's licenses use PDF417 barcodes with AAMVA-compliant data elements. Valydar automatically extracts:

Field	AAMVA Code	Description
Last name	DCS	Family name
First name	DAC	Given name
Middle name	DAD	Middle name
Date of birth	DBB	MMDDYYYY format
Sex	DBC	Gender code
Eye color	DAY	Eye color code
Document number	DAQ	License/ID number
Expiry date	DBA	MMDDYYYY format
Address	DAL-DAM	Street, city, state, postal code
Height	DAX/DCE	Height in ft/cm
Weight	DAW/DCH	Weight in lbs/kg

Cross-Validation

When both barcode and MRZ data are available, Valydar compares:

• Document number — barcode value must match MRZ document number
• Name — barcode last name must match MRZ primary identifier
• Date of birth — AAMVA MMDDYYYY converted to ISO format and compared to MRZ DOB

Example: Matching Data

{
  "mrz_matches_barcode": true,
  "barcode_matches_viz": true,
  "discrepancies": []
}

Example: Mismatch Detected

{
  "mrz_matches_barcode": false,
  "barcode_matches_viz": true,
  "discrepancies": [
    "document number mismatch: barcode='D1234567', mrz='S9876543'"
  ]
}

Result Structure

The barcode check result is included in the verification's checks_results:

{
  "type": "document",
  "result": "passed",
  "details": {
    "barcodes": [
      {
        "format": "pdf417",
        "raw_text": "DCSDOE<<JOHN<<<<<<<<<<<<<<<<<<<<<<<...",
        "position": { "x": 50, "y": 200, "width": 400, "height": 80 }
      }
    ],
    "barcodes_detected": 1,
    "barcode_formats": ["pdf417"],
    "barcode_cross_validation": {
      "mrz_matches_barcode": true,
      "barcode_matches_viz": true,
      "discrepancies": []
    }
  }
}

Tips

• Ensure the barcode area is clearly visible and not obscured
• Higher resolution images improve barcode detection accuracy
• For driver's licenses, the back of the card typically contains the PDF417 barcode
• Cross-validation failures may indicate document tampering — review manually